Application of chromium-silicon cluster for selective removal of arsenic and sulfide from wastewater.

The development of industrialisation increases the abundance of heavy metals, anionic, and harmful gases in the environment. Several techniques are already being used for the removal of different kinds of contaminants, but most of them are far away from their optimum performance. Among different approaches, the capturing of water and air pollutants by functionalised materials has been investigated widely due to cost-effectiveness, and high efficiency. From this point of view, silicon-based nanoclusters have attracted much attention due to their outstanding performance in terms of sensing properties. In the present work, we have applied the CrSi14 cluster for selective capturing of environmental pollutants. To this end, the adsorptions of heavy metal ions (As3+, Pb2+, Cd2+, Hg2+), inorganic anions (CN−, S2−, NO2−), and gas molecules (CO, N2, CH4, CO2, NO2, H2S) on the pristine CrSi4 cluster (PC) and the functionalised cluster (FC) by 1-ethyl-3-methyl imidazolium have been investigated using first-principles methods. The results indicate that PC is not only sensitive to capture As3+ but also acts highly selective so that other examined metals would not interfere with the arsenic removal. The PC also exhibits high sensitivity toward S2- and can be considered as a prominent sorbent for the removal of sulfide. [ABSTRACT FROM AUTHOR]